The present invention relates to a bar code forming method by which the bar code is formed on a resin substrate by a hot stamping die, and to an APS film cartridge on which a bar code is formed.
In a photographic film cartridge according to the standard of the advanced photo system (hereinafter, called APS film cartridge), the photographic film is wound around a resin spool, and covered by a resin film magazine. On one end of this spool, a data disk as the resin substrate integrally provided with the spool is provided, and the bar code displaying the film data such as the film sensitivity and the number of exposures, is recorded. This bar code can be formed by various methods, and for example, in Japanese Tokkaihei No. 8-254794, a method by which a low level pattern using the data disk surface (black) as it is, and a high level pattern in which the member having the large reflection factor (a transfer material such as the transfer foil) is thermally transferred on the disk surface, are structured and provided, is disclosed. This is a method by which the bar code is provided by so-called hot stamping.
In the hot stamping by which the bar code is formed on the resin substrate, transferring is conducted, at the time of heating and pressing, in such a manner that the resin data disk surface is slightly melted, and the transfer foil as the transfer material is stuck in the data disk. A sectional view of the conventional bar code forming portion of the data disk by the hot stamping after transferring is as shown in FIG. 6. A portion which is heated and pressed by the hot stamping, is a concave portion 31, and the outside of the concave portion is formed into a convex portion 32 by the melt resin. The inclined surface connecting the concave portion 31 and the convex portion 32 is a tapered portion 34. Further outside the convex portion 32 is the resin substrate surface 33 of the original data disk which is not affected by the heating and pressing by the hot stamping, and this is the low level pattern LP. The periphery of the concave portion 31 is rimmed by the resin convex portion 32 into the shape of just a plate of the hot stamping.
On the bar code forming surface which is formed by such the hot stamping, and has the concave portion 31 and convex portion 32 as shown in FIG. 6, it is found that, depending on the shape of the concave portion 31 and the convex portion 32, or the condition of formation of the bar code, the misconception of the bar code reading sensor easily occurs. Specifically, in the APS camera whose sensor has the high sensitivity, it is found that this tendency is more conspicuous.
The object of the present invention is, in the bar code forming method in which the transfer material is heated and pressed by the hot stamping die and the bar code is formed on the resin substrate by the transferring, to provide a bar code forming method to form the bar code having the quality by which the bar code reading sensor does not cause the misconception of the reading, and to provide an APS film cartridge on which the bar code by which the bar code reading sensor does not cause the misconception of the reading, is formed.
The above described object of the invention can be attained by one of the following structures (1)-(19).
(1) A bar code forming method, which has the step of:
forming the bar code which satisfies the following conditions, by transferring at least one portion of the transfer material onto the resin substrate by heating and pressing the transfer material onto the resin substrate, wherein, when the difference of the height between the concave portion formed on the resin substrate by the heating and pressing, and the convex portion protruding on the periphery of the concave portion, is h, and the distance between the top of the convex portion and the edge of the convex portion side of the concave portion, is d, 0.01 mmxe2x89xa6hxe2x89xa60.05 mm, and d less than 0.1 mm.
(2) In the method of the structure (1), the step for forming the bar code is conducted by heating and pressing the transfer material by the hot stamping die.
(3) In the method of the structure (2), the angle xcex83 formed between the concave portion, and the tapered portion connecting the concave portion to the convex portion, is not more than 135xc2x0.
(4) In the method of the structure (2) or (3), the angle xcex81 formed between the pressing surface of the hot stamping die by which the resin substrate is heated and pressed through the transfer material, and the side surface connected to the pressing surface, is not larger than 90xc2x0.
(5) In the methods of the structures (2) to (4), a supporting member is provided on the rear side of the surface of the resin substrate on which the bar code is formed, and an elastic body is provided on the surface which is in contact with the resin substrate, of the supporting member.
(6) In the method of the structure (5), the elastic body is rubber, and the thickness of the rubber is 0.5-2 mm, and the rubber hardness is 70 degrees xe2x88x92100 degrees.
(7) In the method of the structure (2), the difference of the height k between the concave portion, and the resin substrate surface which is not affected by the heat by the heating and pressing, is not smaller than 1/10 times and not more than 1/5 times of the amount of undulation in the bar code forming portion of the resin substrate.
(8) In the methods of the structures (2) to (7), the amount of the undulation in the bar code forming portion of the resin substrate is not more than 30 xcexcm.
(9) In the methods of the structures (2) to (8), by setting the temperature of the leading edge portion contacting with the resin substrate of the hot stamping die to 120xc2x0 C.-180xc2x0 C., and the time of the heating and pressing to not longer than 0.4 sec, the difference of the height is made to not smaller than 0.01 mm, and not more than 0.05 mm.
(10) In the methods of the structures (2) to (9), the surrounding of the heat transfer portion of the hot stamping die is covered by the heat insulating material.
(11) In the methods of the structures (2) to (10), the resin substrate is the data disk of the APS film cartridge.
(12) In the method of the structure (1), d greater than 0.
(13) The bar code forming method, which having the following step: a step in which the bar code is formed in such a manner that at least one portion of the transfer material is transferred onto the resin substrate, by heating and pressing the transfer material onto the resin substrate by the hot stamping die so that the following conditions are satisfied, wherein, when the temperature of the leading edge portion of the hot stamping die is T, the pressing force by the hot stamping die is F, and the pressing time of the hot stamping die is t, 120xc2x0 C.xe2x89xa6Txe2x89xa6180xc2x0 C., 100 kgfxe2x89xa6Fxe2x89xa6400 kgf, and 0.2xe2x89xa6txe2x89xa60.4.
(14) In the method of the structure (13), when the cooling time is S, the heating and pressing is carried out so that the condition of 0.2 secxe2x89xa6Sxe2x89xa60.4 sec is satisfied.
(15) In the method of the structure (13), the load deflection temperature of the resin substrate is 100-110xc2x0 C. when the load is 18.5 kgf/cm2.
(16) In the method of the resin substrate is 100-110xc2x0 C. when the load is 18.5 kgf/cm2.
(17) In the film cartridge, a spool around which the film is wound, and the data disk which is arranged on the spool, and has the resin substrate in at least one portion, wherein the data disk has the bar code formed by heating and pressing the transfer material, and the bar code portion satisfies the following conditions: when the difference of the height between the concave portion formed on the resin substrate by the heating and pressing, and the convex portion protruding on the periphery of the concave portion, is h, and the distance between the top of the convex portion and the edge of the convex portion side of the concave portion, is d, 0.01 mmxe2x89xa6hxe2x89xa60.05 mm and d less than 0.1 mm.
(18) In the film cartridge of the structure (17), the film cartridge is the APS film cartridge.
(19) In the film cartridge of the structure (17), the bar code portion is formed by the hot stamping die.
Further, the preferred structures 1-11 are as follows.
1. A bar code forming method, in which the transfer material is heated and pressed, and the bar code is formed onto the resin substrate by transferring by the hot stamping die, the bar code forming method is characterized in that: after the formation of the bar code, the difference of the height h between the concave portion formed on the resin substrate by the heating and pressing by the hot stamping die, and the convex portion protruding on the periphery of the concave portion, is not smaller than 0.01 mm, and not more than 0.05 mm, and the distance d between the top of the convex portion and the edge of the convex portion side of the concave portion, is not larger than 0.1 mm.
2. The bar code forming method according to the method 1, wherein the angle xcex83 formed between the concave portion, and the tapered portion connecting the concave portion to the convex portion, is not more than 135xc2x0.
3. The bar code forming method according to the method 1 or 2, wherein the angle xcex81 formed between the pressing surface of the hot stamping die to heat and press onto the resin substrate through the transfer material, and the side surface connecting to the pressing surface, is not larger than 90xc2x0.
4. The bar code forming method according to any one of the methods 1-3, wherein a supporting member is provided on the rear side of the surface of the resin substrate on which the bar code is formed, and an elastic body is provided on the surface of the resin substrate with which the supporting member comes into contact.
5. The bar code forming method according to the method 4, wherein the elastic body is rubber, and the thickness of the rubber is 0.5-2 mm, and the rubber hardness is 70 degrees to 100 degrees.
6. The bar code forming method according to any one of the methods 1-5, wherein the difference of the height k between the concave portion, and the surface of the resin substrate which is not affected by the heating of the hot stamping die, is 1/5 to 1/10 of the amount of the undulation in the bar code forming portion of the resin substrate.
7. The bar code forming method according to any one of the methods 1-6, wherein the amount of the undulation in the bar code forming portion of the resin substrate is not larger than 30 xcexcm.
8. The bar code forming method according to any one of the methods 1-7, wherein, when the temperature of the leading edge portion which is in contact with the resin substrate of the hot stamping die is 120xc2x0 C.-180xc2x0 C., and the heating and pressing time is not more than 0.4 sec, then, the difference of the height h is not smaller than 0.01 mm, and not more than 0.05 mm.
9. The bar code forming method according to any one of the methods 1-8, wherein the surrounding of the heat transfer portion of the hot stamping die is covered by the heat insulating material.
10. The bar code forming method according to any one of the methods 1-9, wherein the resin substrate is the data disk of the APS film cartridge.
11. The APS film cartridge having the bar code formed by heating and pressing the transfer material by the hot stamping die, the APS film cartridge is characterized in that: after the formation of the bar code, the difference of the height h between the concave portion formed on the resin substrate by the heating and pressing by the hot stamping die, and the convex portion protruding on the periphery of the concave portion, is not smaller than 0.01 mm, and not more than 0.05 mm, and the distance between the edge of the concave portion side of the convex portion and the edge of the convex portion side of the concave portion, is not larger than 0.1 mm.